This invention relates to a radio communication system for carrying out a communication between a master station and a plurality of slave stations by time division multiple access (TDMA).
In general, it is known that a radio communication system comprises a master station and a plurality of slave stations each of which communicates with the master station by time division multiple access. Such a radio communication system is disclosed as a conventional radio communication system in Japanese Patent Publication Tokkai Syo 59-34738 (34738/1984). In the conventional radio communication system, a specific one of the slave stations transmits a specific transmission signal to the master station by using a specific time slot which is assigned to the specific slave station. When the master station receives the specific transmission signal as a specific reception signal, the master station extracts a slave clock signal from the specific reception signal as will be later be described. The master station compares the slave clock signal with a reference clock signal to obtain a phase difference data representative of a phase difference between the slave clock signal and the reference clock signal. The phase difference data is transmitted from the master station to the specific slave station. The specific slave station controls the phase of a transmission data in accordance with the phase difference data. In other words, the specific slave station compensates a phase variation between the master station and the specific slave station in accordance with the phase difference data.
Inasmuch as the master station is connected to each of the slave stations by a radio channel, the transmission signal on the radio channel may be inevitably subjected to fading. As a result, error may occur in the phase difference data by fading. When the error occurs in the phase difference data by fading, it is difficult for the specific slave station to compensate the phase variation between the master station and the specific slave station. As a result, it is difficult to carry out a data transmission in the conventional radio communication system with a high reliability.